Prior to ‘Guardians of the Galaxy’, writer/director James Gunn began his career in the grungy stomping grounds of Troma and worked his way up in the industry through horror. In the wake of his huge Marvel success, Gunn dusted off his old screenplay for ‘The Belko Experiment’. The nasty ultra-violent satire should freak out some folks at Disney in all the best possible ways.

It’s easy to imagine Gunn pitching ‘The Belko Experiment’ as “Office Space meets Battle Royale.” That’s what he wrote, a movie which starts as a satire of cubical drudgery but soon transforms into a cynical commentary on the uncomfortable level of violence found just below the surface of the human condition. Thankfully, Gunn being Gunn, the flick is also playful and goofily entertaining while spilling guts all over the floor and making humans look like vicious animals who don’t play well in teams.

The film takes place in a special office of a U.S. multinational corporation that is for some reason located in the middle of Colombia. All the employees are imports from the States, a motley crew of white collar wage slaves who love, loathe, and make each other feel awkward day-in and day-out. John Gallagher, Jr. is our lead, Michael. He’s too cool to be an office drone, going through his days with just a little bit of detachment. He’s got an office romance brewing with a girl named Leandra (Adria Arjona). He has a mildly combative relationship with his stuffy superiors (John C. McGinley and Tony Goldwyn). He’s also surrounded by a gang of misfits played by recognizable character actors including Michael Rooker, Sean Gunn (the writer’s brother), Josh Brener, Melonie Diaz and others. So far, so ‘Dilbert’.

Then, one day, things change. All the windows in the building shutter up and the doors are locked. A voice announces that the workmates must kill one employee or three will die. Obviously, they don’t start killing right away because they aren’t monsters. But then three heads explode and the survivors are told that 20 more staff members must be murdered by the team or 30 will die. That’s when things get interesting.

Gunn’s script is cackling with morbid wit and deeply disturbing drama. The concept could be played as either splatstick comedy or with nasty sincerity, and Gunn never quite settles on one specific tone. The movie wavers freely from wacky silliness to stone-faced silent tragedy. At times, that can make the film as unbalanced as it sounds, but for the most part it works. The disturbing sequences cut deep and the laughs cut just as deeply in their own way. Gunn wisely doesn’t let the story devolve into ‘Lord of the Flies’ immediately. Instead, he slowly builds that up with characters believably becoming psychotic when pushed to their limits or desperately trying to maintain sanity in a situation designed to destroy them. It’s a nasty bit of entertainment, but also quite clever. It sits well with the morbidly hilarious genre mind-fucks that Gunn made in the past, such as ‘Slither’ and ‘Super’.

Of course, Gunn is a Marvel man now, so directing ‘The Belko Experiment’ didn’t fit into his schedule. That job fell on ‘Wolf Creek’ director Greg McLean, and it was a perfect choice. McLean has a sick sense of humor of his own, but makes intense horror flicks that no one would ever dare call comedies despite their many morbid laughs. He plays up the thrills and splatters brains across the wall without a hint of irony. The film is intense. The humor falls into the hands of the performers and the laughs grow increasingly uncomfortable.

It doesn’t hurt that the cast is brilliant, either playing directly into type (Gallagher’s been doing the goofy everyman thing for a while, just never covered in blood before) or wildly going against type for the sake of surprise. (Michael Rooker and John C. McGinley are both cast well, but not necessarily for the reasons you’d expect.) McLean and the cast ground the ridiculous comic book scenario about as well as any filmmaking team possibly could, and the concept carries enough tension to keep the sick fun pumping along with the fake blood.

Unfortunately, the uneasy tone that makes much of ‘The Belko Experiment’ so compelling ends up becoming a hindrance. It’s obvious that the filmmakers weren’t quite sure how to wrap things up, and the finale feels a bit unfinished and unsatisfying. It also doesn’t help that there are so many clear cinematic/cultural influences in play that ‘The Belko Experiment’ always feels more like a movie mixtape than anything original. Still, for the specific brand of sick puppy who finds the concept for ‘The Belko Experiment’ funny yet unsuited for pure comedy, this is a bit of dirty genre fun that’s hard to resist. It’s unlikely that this will ever become a cult classic, but it’s a great way to spend a blood-soaked hour of cynical entertainment that makes you smile and feel shitty all at once. That may not be for everyone, but those who have just the right perverse sensibility will find ‘The Belko Experiment’ to be a depraved delight.